RESUMO
Interest in the production of renewable chemicals from biomass has increased in the past years. Among these chemicals, carboxylic acids represent a significant part of the most desirable bio-based products. Xylonic acid is a five-carbon sugar-acid obtained from xylose oxidation that can be used in several industrial applications, including food, pharmaceutical, and construction industries. So far, the production of xylonic acid has not yet been available at an industrial scale; however, several microbial bio-based production processes are under development. This review summarizes the recent advances in pathway characterization, genetic engineering, and fermentative strategies to improve xylonic acid production by microorganisms from xylose or lignocellulosic hydrolysates. In addition, the strengths of the available microbial strains and processes and the major requirements for achieving biotechnological production of xylonic acid at a commercial scale are discussed. Efficient native and engineered microbial strains have been reported. Xylonic acid titers as high as 586 and 171 g L-1 were obtained from bacterial and yeast strains, respectively, in a laboratory medium. Furthermore, relevant academic and industrial players associated with xylonic acid production will be presented.
Assuntos
Biotecnologia , Xilose , Biomassa , Fermentação , Engenharia Metabólica , Xilose/análogos & derivados , Xilose/metabolismoRESUMO
A series of hybrids containing tacrine linked to carbohydrate-based moieties, such as d-xylose, d-ribose, and d-galactose derivatives, were synthesized by the nucleophilic substitution between 9-aminoalkylamino-1,2,3,4-tetrahydroacridines and the corresponding sugar-based tosylates. All compounds were found to be potent inhibitors of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in the nanomolar IC50 scale. Most of the d-xylose derivatives (6a-e) were selective for AChE and the compound 6e (IC50â¯=â¯2.2â¯nM for AChE and 4.93â¯nM for BuChE) was the most active compound for both enzymes. The d-galactose derivative 8a was the most selective for AChE exhibiting an IC50 ratio of 7.6 for AChE over BuChE. Only two compounds showed a preference for BuChE, namely 7a (d-ribose derivative) and 6b (d-xylose derivative). Molecular docking studies indicated that the inhibitors are capable of interacting with the entire binding cavity and the main contribution of the linker is to enable the most favorable positioning of the two moieties with CAS, PAS, and hydrophobic pocket to provide optimal interactions with the binding cavity. This finding is reinforced by the fact that there is no linear correlation between the linker size and the observed binding affinities. The majority of the new hybrids synthesized in this work do not violate the Lipinski's rule-of-five according to FAF-Drugs4, and do not demonstrated predicted hepatotoxicity according ProTox-II.
Assuntos
Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Desenho de Fármacos , Tacrina/análogos & derivados , Tacrina/farmacologia , Acetilcolinesterase/metabolismo , Animais , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/síntese química , Galactose/análogos & derivados , Galactose/síntese química , Galactose/farmacologia , Humanos , Camundongos , Simulação de Acoplamento Molecular , Ribose/análogos & derivados , Ribose/síntese química , Ribose/farmacologia , Relação Estrutura-Atividade , Tacrina/síntese química , Torpedo , Xilose/análogos & derivados , Xilose/síntese química , Xilose/farmacologiaRESUMO
BACKGROUND: The present study combines morphological and anatomical studies, cell wall chemical composition analysis, as well as assessment of the nutritional value of Guadua chacoensis foliage leaves. RESULTS: Foliage leaves of G. chacoensis are a promising source of forage because: (a) as a native woody bamboo, it is adapted to and helps maintain environmental conditions in America; (b) leaf anatomical studies exhibit discontinuous sclerenchyma, scarcely developed, while pilose indumentum, silica cells, prickles and hooks are also scarce; (c) it has a high protein content, similar to that of Medicago sativa, while other nutritional parameters are similar to those of common forages; and (d) glucuronoarabinoxylan, the major extracted polysaccharide, has one-third of the 4-linked ß-d-xylopyranosyl units of the backbone substituted mainly with α-l-arabinofuranose as single stubs or non-reducing end of short chains, but also 5-linked α-l-arabinofuranose units, terminal ß-d-xylopyranose and d-galactopyranose units, as well as α-d-glucuronic acid residues and small amounts of its 4-O-methylated derivative. CONCLUSION: These results constitute the first report on this species, and as culms are utilized in constructions and crafts, the remaining leaves, when used as forage, constitute a byproduct that allows an additional income opportunity. © 2016 Society of Chemical Industry.
Assuntos
Ração Animal , Parede Celular/química , Dieta/veterinária , Valor Nutritivo , Folhas de Planta , Poaceae , Ruminantes , América , Animais , Arabinose/análogos & derivados , Arabinose/análise , Conservação dos Recursos Naturais , Carboidratos da Dieta/análise , Fibras na Dieta/análise , Proteínas Alimentares/análise , Galactose/análise , Ácido Glucurônico/análise , Células Vegetais/química , Folhas de Planta/anatomia & histologia , Folhas de Planta/química , Proteínas de Plantas/análise , Poaceae/anatomia & histologia , Poaceae/química , Madeira , Xilanos/análise , Xilose/análogos & derivados , Xilose/análiseRESUMO
The water-soluble sulfated xylogalactoarabinans from green seaweed Cladophora falklandica are constituted by a backbone of 4-linked ß-l-arabinopyranose units partially sulfated mainly on C3 and also on C2. Besides, partial glycosylation mostly on C2 with single stubs of ß-d-xylopyranose, or single stubs of ß-d-galactofuranose or short chains comprising (1â5)- and/or (1â6)-linkages, was also found. These compounds showed anticoagulant activity, although much lower than that of heparin. The effect of a purified fraction (F1) on the fibrin network was studied in detail. It modifies the kinetics of fibrin formation, suggesting an impaired polymerization process. Scanning electron microscopy showed a laxer conformation, with larger interstitial pores than the control. Accordingly, this network was lysed more easily. These fibrin properties would reduce the time of permanence of the clot in the blood vessel, inducing a lesser thrombogenic state. One of the possible mechanisms of its anticoagulant effect is direct thrombin inhibition.
Assuntos
Anticoagulantes/farmacologia , Clorófitas/química , Fibrina/metabolismo , Polissacarídeos/química , Polissacarídeos/farmacologia , Animais , Anticoagulantes/química , Configuração de Carboidratos , Avaliação Pré-Clínica de Medicamentos/métodos , Fibrinólise/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Varredura , Coelhos , Alga Marinha/química , Sulfatos/química , Xilose/análogos & derivados , Xilose/químicaRESUMO
Specific rotation ([α](D)) values were calculated for the 15 conformations of xylopyranose that are the most stable in the gas phase and in aqueous solution. The effects of different theoretical descriptions and the medium on the geometry of the conformers and the [α](D) values are evaluated. Differences in [α](D) values found for the same conformer in all descriptions used were smaller than those found between any two different conformers in the same description. The difference between [α](D) values is prominent, even for two conformations that are distinguished from each other only by the orientation of one secondary hydroxyl group. This finding suggests that [α](D) values may potentially be used in the validation of monosaccharide conformations that are theoretically sampled.
Assuntos
Fenômenos Ópticos , Rotação , Xilose/análogos & derivados , Configuração de Carboidratos , Gases/química , Modelos Moleculares , Reprodutibilidade dos Testes , Estereoisomerismo , Água/química , Xilose/químicaRESUMO
La levadura Candida guilliermondii es objeto de estudio debido a su capacidad de producir xilitol aprovechando compuestos hemicelulósicos ricos en xilosa, dado esto, la cepa Candida guilliermondii aislada del fruto del corozo chiquito (Bactris guineensis) fue usada en este estudio con el fin de evaluar su capacidad para producir xilitol sobre un sustrato hidrolizado de cascarilla de arroz. El objetivo de este trabajo fue determinar los parámetros fermentativos como producción de xilitol, productividad volumétrica (Qp) y rendimiento de sustrato en producto (Yp/s) durante la fermentación con la cepa nativa Candida guilliermondii. Se emplearon 200 ml de medio de cultivo hidrolizado de cascarilla de arroz, el cual contenía una concentración de xilosa de 27,5 g/L. La fermentación se llevó a cabo bajo las siguientes condiciones: temperatura 30 ºC, pH del medio 5,8, agitación 120 rpm e inóculo adaptado de 3 g/L. Los resultados mostraron que después de 120 horas de fermentación se obtuvieron 2,6 g/L de xilitol con productividad volumétrica (Qp) de 0,02 g/L-h y rendimiento de sustrato en producto (Yp/s) de 0,13 g/g. De esta manera, la cepa nativa Candida guilliermondii, aislada del fruto de Corozo chiquito (Bactris guineensis), produjo xilitol bajo condiciones específicas de fermentación.
The yeast Candida guilliermondii has been studied due to its ability to produce xylitol in xylose-rich hemicellulosic compounds, Candida guilliermondii strain isolated from the fruit of Corozo chiquito (Bactris guineensis) was used in this study to assess their ability to xylitol production on these substrates. The aim of this study was to determine the fermentation parameters such as xylitol production, volumetric productivity (Qp) and yield of xylitol production (Yp/s) during fermentation with the native strain Candida guilliermondii. Was used 200 ml of culture medium rice husk hydrolysate, which contained a xylose concentration of 27.5 g/L. The fermentation was carried out under the following conditions: temperature 30 ºC, pH of 5.8, agitation 120 rpm and adapted inoculum of 3 g/L. The results showed that after 120 hours of fermentation 2.6 g / L of xylitol was achieved with volumetric productivity (Qp) 0.02 g/L-h and 0.13 g/g yield of xylitol production (Yp/s). The native strain Candida guilliermondii, isolated from the fruit of Corozo chiquito (Bactris guineensis) produced xylitol fermentation under specific conditions.
Assuntos
Fermentação/fisiologia , Fermentação/genética , Fermentação/imunologia , Xilose/análise , Xilose/análogos & derivados , Xilose/classificação , Xilose/fisiologia , Fermento Seco/análise , Fermento Seco/classificação , Fermento Seco/farmacologia , Fermento Seco/genética , Fermento Seco/provisão & distribuição , Fermento Seco/química , Fermento Seco/síntese químicaRESUMO
UNLABELLED: We investigated the antinociceptive effects of AR-A014418, a selective inhibitor of glycogen synthase kinase-3ß (GSK-3ß) in mice. A 30-minute pretreatment with AR-A014418 (.1 and 1 mg/kg, intraperitoneal [ip]) inhibited nociception induced by an ip injection of acetic acid. AR-A014418 pretreatment (.1 and .3 mg/kg, ip) also decreased the late (inflammatory) phase of formalin-induced licking, without affecting responses of the first (neurogenic) phase. In a different set of experiments, AR-A014418 (.1-10 µg/site) coinjected intraplantarly (ipl) with formalin inhibited the late phase of formalin-induced nociception. Furthermore, AR-A014418 administration (1 and 10 ng/site, intrathecal [it]) inhibited both phases of formalin-induced licking. In addition, AR-A014418 coinjection (10 ng/site, it) inhibited nociception induced by glutamate, N-methyl-D-aspartate (NMDA), (±)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD), tumor necrosis factor-alpha (TNF-α), and interleukin-1beta (IL-1ß) by 47 ± 12%, 48 ± 11%, 31 ± 8%, 46 ± 13%, and 44 ± 11%, respectively. In addition, a 30-minute pretreatment with NP031115 (3 and 10 mg/kg, ip), a different GSK-3 ß inhibitor, also attenuated the late phase of formalin-induced nociception. Collectively, these results provide convincing evidence that AR-A014418, given by local, systemic, and central routes, produces antinociception in several mouse models of nociception. The AR-A014418-dependent antinociceptive effects were induced by modulation of the glutamatergic system through metabotropic and ionotropic (NMDA) receptors and the inhibition of the cytokine (TNF-α and IL-1ß) signaling. PERSPECTIVE: These results suggest that GSK-3ß may be a novel pharmacological target for the treatment of pain.
Assuntos
Dor Abdominal/prevenção & controle , Analgésicos/administração & dosagem , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Tiazóis/administração & dosagem , Ureia/análogos & derivados , Dor Abdominal/induzido quimicamente , Agressão/efeitos dos fármacos , Análise de Variância , Animais , Anti-Inflamatórios não Esteroides , Azidas/administração & dosagem , Citocinas/administração & dosagem , Citocinas/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Vias de Administração de Medicamentos , Formaldeído/efeitos adversos , Ácido Glutâmico/efeitos adversos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Masculino , Camundongos , N-Metilaspartato/administração & dosagem , Medição da Dor/métodos , Açúcares Ácidos/efeitos adversos , Ureia/administração & dosagem , Xilose/efeitos adversos , Xilose/análogos & derivadosRESUMO
Four Mexican Nymphaea species, N. ampla, N. pulchella, N. gracilis and N. elegans belonging to subgenera Brachyceras were analyzed. In this work two 5-glycosyl isoflavones, 7,3',4'-trihydroxy-5-O-beta-D-(2''-acetyl)-xylopyranosylisoflavone (1) and 7,3',4'-trihydroxy-5-O-alpha-L-rhamnopyranosylisoflavone (2), were isolated from N. ampla and N. pulchella, respectively, together with other known 3-glycosyl flavones and triterpene saponins from the same four species. The structures were elucidated by 1D and 2D NMR, FABMS, and other spectroscopic analyses. These results confirmed that the four species were different from each other and established that N. pulchella represents a different taxa than N. ampla. In addition, the 5-glycosyl isoflavones could be considered as a taxonomic character of this group of plants.
Assuntos
Nymphaea/química , Ramnose/análogos & derivados , Xilose/análogos & derivados , Isoflavonas/química , Isoflavonas/isolamento & purificação , México , Estrutura Molecular , Ramnose/química , Ramnose/isolamento & purificação , Especificidade da Espécie , Xilose/química , Xilose/isolamento & purificaçãoRESUMO
The effect of xylosides on the synthesis of [35S]-sulfated glycosaminoglycans by endothelial cells in culture was investigated. Ortho-nitrophenyl-beta-D-xylose (10(-3)M) produces a dramatic enhancement on the synthesis of heparan sulfate and chondroitin sulfate secreted to the medium (20- and 100-fold, respectively). Para-nitrophenylxyloside, at the same concentration, produces an enhancement of only 37- and 3-fold of chondroitin sulfate and heparan sulfate, respectively. These differences of action seem to be related with the higher lipophilic character of ortho-nitrophenyl-xyloside. A lower enhancement of the synthesis of the two glycosaminoglycans is also observed with 2-naphtol beta-D-xylose and cis/trans-decahydro-2-naphtol beta-D-xylose. Besides stimulating the synthesis, O-nitrophenyl-beta-D-xylose as PMA [J. Cell. Biochem. 70 (1998) 563] also inhibits [3H]-thymidine incorporation by quiescent endothelial cells stimulated for growth by fetal calf serum (FCS). The combination of xylosides with PMA produced some cumulative effect. PMA stimulates the synthesis of heparan sulfate mainly at G1 phase whereas the highest enhancement of synthesis produced by the xylosides is in the S phase of the endothelial cell cycle.